From our brief survey, we conclude that any suggestion that … Christ rejects certain Mosaic laws as unauthoritative is quite groundless. What He is doing is simply exhibiting the true meaning of the law as a rule for life in the kingdom of God.
Nor can we fairly treat the words by which (according to Mark’s later interpretative comment) Christ ‘declared all food clean’ as implying that He rejected the Old Testament food-law as uninspired and unauthoritative. The subject about which He was speaking was not, after all, food, but defilement; and what He was saying about defilement was that the thing that makes a man unclean in God’s sight is not what he eats, but what comes out of his heart. This only shows that our Lord saw that the uncleanness with which the food-laws dealt was merely ceremonial, not moral or spiritual. It typified the real defilement of sin, but was not to be equated with it. That it was God who had instituted the food-law, presumably to be a constant reminder to His people of the reality of spiritual defilement, Christ was not denying in the least. The effect of His statement was thus to interpret the food-law, and throw light on its real significance, but not in any way to impugn its divine origin, or its binding authority over Himself and His fellow-Israelites.
It seems, then, that all the problem passages in which Christ appears to cast doubt on the inspiration and authority of parts of the Mosaic legislation can be explained, and, indeed, demand to be explained, in a way that is entirely consistent with Christ’s assertion that no jot or tittle should ever pass from the law. Christ knew, of course, that the civil and ritual part of the law, which had been given specifically for the ordering of Israel’s national life in Palestine until Christ should come, would soon cease to apply, when the Israelite state passed away. But when He spoke of the perpetuity of the law, what He had in mind was the moral law, which in different ways both the civil and ritual law had subserved. This, He maintained, was an abidingly authoritative word from the Lord, which, in the final form and application which He Himself had given it, would stand for ever as the law of God for His own people.
I agree with Packer that all the New Testament passages which seem to cast doubt on parts of the Mosaic legislation can be explained, and demand to be explained; I don’t always agree with him on how they should be explained… and I view that difference as being a result of the consequences of the re-planting of the Jewish people in their homeland, and the discovery of the Dead Sea Scrolls—two factors which have radically impacted how the Church reads (and how accurately we are able to read) the New Testament.
Also, I struggle with, on the one hand, but agree with on the other hand, the categorization of the law into moral, ceremonial and civil. I think Packer and most other Reformed scholars misunderstand how Christ/the Bible see the ceremonial aspects of the Law, and this causes a weakness in our theology of sanctification. However, we do not thus lose so critical a linchpin as when we reject the abiding prescriptive force of Old Testament law as being the foundation of New Testament explication, amplification and application.
For example, having lost their moral foundation, the zeitgeist of contemporary Christianity is moving in the direction of concluding that just as Christ explicitly overturned the food laws (a mistaken presumption), by not mentioning homosexuality he implicitly condoned monogamous, committed same-sex relationships. In the same vein, we must ask: upon what coherent basis does your theological reading of Scripture account for the abiding prohibition of bestiality or a fiat monetary system? If it cannot do so (and no perspective of discontinuity can) then we have a serious problem on our hands, a problem well highlighted by our current circumstances within both secular culture and the Western Church.
As it relates to the tri-fold division of the law, I think it is accurate to speak of a ceremonial, civil and moral categorization of the laws on an observational basis—meaning, one can’t deny that some instructions pertain to clearly ethical/behavioral issues, and others clearly pertain to the conduct of worship, while others clearly pertain to the theocratic judicial system.
Unfortunately, we often move from an observational analysis to thinking of the law as if it was conceived of in a three-part manner. As if God gave us a ceremonial law, a civil law and a moral law. Rather, the truth is (as the dispensationalist protests), the Mosaic law was delivered as a unified whole. This thinking leads us to thinking/behaving as if the ceremonial no longer
applies, etc. This is where we get in trouble. The reason the ceremonial laws are no longer practiced is not because they’ve been superseded in Christ, but because it would be unlawful to do so.
Let’s take the biblical festivals as an example. The Spring feasts point to events in the course of redemptive history that have already happened: Passover=Redemption, First Fruits=Resurrection, and Pentecost=Revelation. The Fall Feasts, on the other hand, point to parts of redemptive history that have not yet been witnessed: Trumpets=Return, Atonement=Glorification, Tabernacles=God dwelling with man, the marriage feast of the lamb, the inauguration of the world to come. By observing the primitive Church in Acts and the 1st century we see that they did not stop celebrating these festivals, or stop the Spring feasts but continue the Fall feasts.
Unfortunately, however, due to our separation from our Jewish Roots and the onset of supersessionism as a theological perspective, much of the Church has come to believe that fulfillment equates to uselessness. Nothing could be further from the truth; when Christ is revealing to his disciples that he is about to fill Passover full (a useful way to more accurately think of “fulfill”) by becoming their sacrificial lamb, his words to them were the opposite of stop: “Do this in remembrance of me.”
In other words, Passover is clearly a ceremonial instruction, but Jesus didn’t introduce its cessation, he filled its significance full that it might becomes so much more to us than just a remembrance of our rescue from Egypt and from the hand of the death angel.
The Churches of the Reformation from the very beginning distinguished between the law and the gospel as the two parts of the Word of God as a means of grace. This distinction was not understood to be identical with that between the Old and the New Testament, but was regarded as a distinction that applies to both Testaments. There is law and gospel in the Old Testament, and there is law and gospel in the New. The law comprises everything in Scripture which is a revelation of God’s will in the form of command or prohibition, while the gospel embraces everything, whether it be in the Old Testament or in the New, that pertains to the work of reconciliation and that proclaims the seeking and redeeming love of God in Christ Jesus. And each one of these two parts has its own proper function in the economy of grace. … Both are subservient to the same end, and both are indispensable parts of the means of grace. This truth has not always been sufficiently recognized. The condemning aspect of the law has sometimes been stressed at the expense of its character as a part of the means of grace. Ever since the days of Marcion there have always been some who saw only contrast between the law and the gospel and proceeded on the assumption that the one excluded the other.”
 J.I. Packer, “Our Lord’s Understanding of the Law of God.” The Campbell Morgan Memorial Bible Lectureship. No. 14, 1962. Published on-line at http://www.biblicalstudies.org.uk/article_law_packer.html.
 L. Berkhof, Systematic Theology (Grand Rapids, MI: Wm. B. Eerdmans publishing co., 1938), 612.